Lifting jack



May 26, 1925.

G. JENSEN LIFTING JACK Filed Aug. 14, 1924 3 Sheets-Sheet 1 G. JENSENLIFTING JACK May 26, 1925.

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G. JENSEN LIFTING JACK Filed Aug. 14, 1924 3 Sheets-Sheet 5 H I n wmv lw um m 6 m IN w Patented May 26, 1925.

UNITED STATES I 1,538,896 PATENT OFFICE.

GUNNAB JENSEN, OF RAGINE, WISCONSIN, ASSIGNOR TO WALKER MANUFACTURINGCOMPANY, OF RACINE, WISCONSIN, A CORPORATION OF WISCONSIN.

LIFTING JACK.

Application filed August 14, 1924. Serial No. 782,023.

To all whom it may concern:

Be it known that I, GUNNAR JENSEN, a subject of the King of Denmark,residing at Racine, in the county of Racine and State of Wisconsin, haveinvented certain new and useful Improvements in Lifting Jacks, of whichthe following isiagspecification.

This invention relates to thlfclassofdevices known as lifting jacks, andmore particularly to such a device designed to have an exceptionallylong lift in proportion to its size and height when in collapsed orlowered position.

While ,the uses for such a jack are innumerable, it is especiallyadapted for advantageous use in the automotive industry with the newoversized or balloon tires. For this use it is desirable to have a jackwhich is compact and of small vertical height when lowered, in order tobe placed underthe low axle or other frame part when the tire iscollapsed, and capable of a comparatively long lift to elevate the carabove its normal driving height in order that the tire may be changed.

The jack is of that type employing a plurality of screws working onewithin another and each contributing its share to the total lift of thejack. According to this invention the screws are telescoped or nestedwithin one another and within the standard of the jack when in loweredposition, and driving connections are provided whereby upon a continuousrotation of the driving means, which may be operated from a distance,the screws are simultaneously operated so that each will exert itslifting power upon the load. According to the preferred embodiment ofthe invention here shown by way of example, two nested screws areemployed,

the outer screw being an exteriorly threaded sleeve which meshes with astationary nut formed in the standard of the jack. The inner screwmeshes within a nut formed in the upper end of the outer screw sleeve.Means are provided to hold the inner screw against rotation at all timesbut allow it to move vertically. Driving means, keyed to the outersleeve, rotate the same continuousy in one direction thusmoving itupthrough the stationary nut, and at the same time the outer sleeve actsas a nut to elevate the inner non-rotary screw. Rotation of the-drivingmeans in the reverse direction will lower the parts to the originalposition.

forth in more detail hereinafter, providing improved means for holdingthe inner screw against rotation while it allows the screw to move upcompletely out of the standard,

and providing a compact and sightly jack, in whichtheparts are easilyassembled and readily accessible.

Other objects and advantages of the invention will be readily apparentfrom the following detailed description of several different types ofjacks embodying the principles of this invention.

In the accompanying drawing:

Fig. 1 is a central vertical section through one of the preferred formsof jack, showing the jack in partially elevated position.

Fig. 2 is a transverse section taken substantially on the line 2-2 ofFig. 1.

Fig. 3 is a transverse section taken substantially on the line 3-3 of-Fig. 1.,

Fig. 4 is a central vertical section through a slightly modified form ofthe jack.

Fig. 5 is a similar view through another modification.

Fig. 6 is a transverse section taken substantially on the line 66 ofFig. 5.

Fig. 7 is a central vertical section through another modification.

Fig. 8 is a horizontal section taken sub stantially on the line 8-8 ofFig. 7.

Fig. 9 is a horizontal section taken substantially on the line 99 ofFig. 7.

Fig. 10 is an elevation of the jack shown in Figs. 7, 8 and 9, on asomewhat smaller scale.

I will first describe the very similar forms of jacks shown in Figs. 1to 10 inclusive, and will-refer more particularly to the forms shown inFigs. 1, 2 and 3. The stationary standard for the jack comprises asubstantially cylindrical hollow casting 1, having a broad supportingbase 2. At its upper end the standard 1 is formed with an integral.upwardly extending annular ring 3 which is in'teriorly threaded to.form 'a stationary nut. A rotary driving member 4, here shown as abeveled gear, is journaled and supported upon the upper end of nut 3. Acover plate 5', having a bearing at 6 for the upper portion of gear 4,is removably secured to the standard 1 by screws or similar devices 7Journaled in an extension 8, at

one side of cover plate 5, is a short stubshaft 9, having a smallbeveled pinion 10 formed at its inner end or keyed thereto. Beveledpinion 10 meshes with and drives the beveled gear 4. The outer end ofshaft 9 is provided with a socket 11, to cooperate with any suitableform of removable handle whereby the jack may be operated from adistance. It will be noted that the shaft 9 tilts upwardly so that theoperators end of the handle will be elevated to a convenient position.

The lifting members comprise a pair of oppositely threaded screw members12 and 13, which are nested one within the other wherrtl ie j ack is inlowered position. The outer screw 12 is iiithaform' Ora hollow sleeveexteriorly threaded to mesh with the stationary nut 3. Keys 14 aremounted in sockets 15 in opposite sides of gear 4, these.

keys engaging in vertically extending keyways 16 formed in diametricallyopposite sides of the exterior portion of sleeve12. A downwardlyextending annular flange 17 on the lower side of gear 4, engages acorresponding groove or channel in the top of nut 3 to center the gear.One of the keys 14 has been omitted, at the right of Fig. 1, to moreclearly illustrate the sockets 15 and flange 17. The central opening ingear 4 is of such size that the screw sleeve 12 can move freelyvertically therethrough, but the gear 4 and sleeve 12 will always rotateas a unit due to the engagement of the keys 14 in the keyways 16 in thescrew. Ihe inner screw 13 meshes with a nut 18 formed in the upper endof the outer screw sleeve 12. A load-supporting cap 19, rockinglymounted as hereinafter described, is secured to the upper end of theinner screw 13. Each of the two screws is of substantially the sameheight as the standard, and when the ack is in lowered position areenclosed completely within the standard except for the loadsupfiortingcap 19.

ovably suspended within the annular space 20 between the inner and outerscrews, is a comparatively thin metallic tube or sleeve 21. At is lowerend this sleeve is provided with outwardly extending lugs 22 whichtravel up and down in slots 23 formed vertically in diametricallyopposite sides 9f the standard 1. Vertically extending slots 24 are cutin diametrically opposite sides of Cir the tube 21, as here shown theseslots being spaced ninety degrees from the lugs 22. Short pins orprojections 25 at the lower end of screw 13 are adapted to travel up anddown in the slots 24. It will be noted that the tube 21 is lockedagainstrotation. at all times by the lugs 22 moving in the slots 23 inthe stationary standard 1, and that in turn the inner screw 13 is locked.to the tube 21 by means of the pins 25 engaging in the slots 24 in thetube. By this means, al-

though the screw 13 may be elevated bodily completely out of thestandard 1, as shown in Fig. 1, it is at all times locked to thestandard in such a manner that it cannot rotate. This improved lockingmeans is housed at all times within the standard and lifting members,and does not add to the size of the jack assembly, nor present anyunsightly projections upon the exterior thereof.

In operation, the jack, in collapsed or l0wered position as shown inFig. 5 with a slightly modified form of jack, is inserted beneath themember to be elevated. The removable handle is-thenirgerted in thesocket 11, and, with the parts threaded as shown in the drawing, isrotated continmin a clockwise direction. gear: 4 and screw sleeve 12in acounter clockwise direction, as viewed from above, and will causethis'outer screw 12 to elevate itself through the stationary nut 3. Atthe same time, the inner screw 13, which is not allowed to rotate, willbe carried bodily upward by the sleeve 12, and furthermore will beelevated with relation to sleeve 12 by the rotary nut 18 formed in theupper end of the sleeve. The two screws 12 and 13 will be simultaneouslyoperated to each contribute its share to the elevating process,regardlless of whether any load is carried by the load-supporting cap 19or not. It will be noted that the extreme height of the jack when inextended position is nearly three times its height when in lowered orcallapsed position. \Vhen the jack is to be lowered, the handle isrotated continuously in the opposite direction, and the parts resumetheir original'position by a movement exactly the reverse of thosepreviously described.

In the modification shown in Fig. 4, the stationary nut 26, instead ofbeing formed as an extension of the standard 1, is formed integrallywith the cover plate 27 and located above the driving gear 28. Thestubshaft 29, corresponding to the shaft, 9 previouslysdescribethisjournaled -in a housing extension 30 at one side of the upper end ofstandard 1. T he shaft 29 carries the beveled pinion 31 meshing with anddriving the gear 28; Driving gear 28 is journaled upon an annular flange32 at theupper end of standard 1. and both screws move freely up anddown through the standard. Otherwise this jack is constructed andoperates substantially the same as the form previously described.

The modification shown in Figs. 5 and 6 is similar to that shown in Fig.4, with the exception that a different device is used to hold the innerscrew against rotation. A rod or bar 33, having a square or otherangular cross section, replaces the tube 21 previously described. Thismember 33 projects This will rotate m up within the inner screw 34 whichis hollow, and has a sliding fit within a correspondingly shapedaperture 35 in the lower end of the screw. A plate 36 secured to thelower end of rod 33, has lugs or projections 37 which move up and downin vertical slots or grooves 38 in the standard 1. Lugs 37 preventrotation of the rod 33, which in turn, due to its angular cross section,prevents rotation of the inner screw 34:. At the same time the screw 34can move freely upwardly until the head 39 on rod 33 is en countered,after which rod 33 can slide upwardly through the standard with the lugs37 traveling up in the slots 38. Otherwise this jack operates similarlyto the form previously described.

The modification shown in Figs. 7 to 10 inclusive illustrates thesubstitution of a worm and worm-wheel drive for the beveled gear drivepreviously described. In this modification, the stationary nut 3 isformed at the top of the standard 1, as in the form shown in, Fig. 1.The worm-wheel 40, which has straight vertical teeth 41 similar to aspur-gear, is journaled at 42 about the outside ofthe nut 3 and has aninwardly extending flange 43 su orted upon the upper end of the nut. eys44 placed in recesses in the flange 43, engage in vertical slots orgrooves 45 in the outer screw sleeve 12 so that the worm-wl1ee l andsleeve will always rotate as a unit. Aworm 46, mounted on an inclinedaxis as shown in Fig. 10 within a housing extension 47*of cover plate 48meshes with and drives the worm-wheel 40. An anti'friction thrustbearing 49 is provided between the worm46 and one face of the housing,and a socket 50 is provided at the outer end of worm shaft 51 toaccommodate the removable operating handle. The inclined position ofworm 46 serves the double function of permitting the worm teeth toproperly mesh with the vertical teeth 41 of worm-wheel 40, and alsotilts the operating handle u wardly at the proper convenient angle.he-sleeve or-tube. 21 and cooperating parts for holding the inner screw13 against rotation are substantially the same as described inconnection with Figs. 1 to 4 above. The use of this worm drive asshownin Figs. 7 to 10, provides a greater gear reduction than ispossible with the beveled gearing pa'eviously shown, and hence adaptsthisjaekfor lifting heavier loads.

As shown more particularly in Fig. 7, the load-supporting cap 19 isprovided with an interior recess 52 which loosely surrounds a reducedextension at the top of the inner,

screw 13, the cap resting upon the rounded surface 53 at the top of thisextension. A pin or rivet 54 in the cap projects. loosely into anopening 55 in the screw to prevent removal of the cap 19. By this meansthe load-supporting cap 19 is allowed a certain universal freedom of.movement so that itinay adapt itself to any slight tilting of the loadsupported by the jack without necessitating any corresponding tilting ofthe jack itself. It is to be understood that this same form of cap maybe used on any of the other forms of jacks previously described.

It will be noted that all of these forms of jacks are comparativelysmall and compact when in lowered position so that they may be stored ina small space, and may easily be inserted for operation beneath verylow-lying parts. At the same time the jacks have an extraordinary longlift, and are easily operated by continuous rotary movement of thehandle in one direction, through reduction gearing which makes theturning efi'ort light, even when handling heavy loads.

I claim:

1. A lifting jack comprising a hollow standard, a stationary nut in theupper end of the standard, a pair of screws each of substantially thesame height as the stand.- ard, and adapted to nest within one anotherand within the standard, the outer screw being in the form of a sleeveexteriorly threaded to mesh with the nut, and interiorly threaded at itsupper end to mesh with the inner screw, there remaining an annular spacebetween the screws below their threaded connection, means for rotatingthe outer screw, and means having sliding engagement with the standardand inner screw for holding this screw against rotation, but allowing itto move vertically, this holding means being housed within the annularspace between the screws when they are lowered to nested position.

2. A lifting jack comprising a hollow standard, a stationary nut in theupper end of the standard, a pairof screws each of substantially thesame height as the standard, and adapted to nest within one another andwithin the standard, the outer screw being in the form of ,a sleeveexteriorly threaded to mesh with the nut, and interiorly threaded at itsupper end to mesh with the inner screw, means for rotating the outerscrew, a tubular member positioned between the inner and outer screws,and pin and slot connections between the tubular member and the standardand inner screw, whereby these members are all vertically movable withrespect to one another but no relative rotation is permitted between theinner screw and the standard.

3. A lifting jack I comprising a hollow standard, a stationary nut inthe upper end of the standard, a pair of screws each of substantiallythe same height as the standard, and adapted to nest within one anotherand within the standard, the outer screw being in the form of a sleeveexteriorly threaded to mesh with the nut, and interiorly threaded at itsupper end to mesh slot, and a projection on the lower end of with theinner screw,- means for rotating the the tubular member movable inavertical outer screw, and a tubular member posislot in the standard,whereby the tube and tioned between the inner and outer screws innerscrew are vertically movable with reand provided with a longitudinallyextendspect to the standard and each other, but ing slot, there being aprojection on the none of these parts can rotate.

lower end of the inner screw movable in the GUNNAR JENSEN.

